A rescue worker with a dog looks for victims at China's Henan Province site where an expressway bridge collapsed after a truck laden with fireworks exploded Thursday, Feb. 1, 2013. / AP

by Calum MacLeod, USA TODAY

by Calum MacLeod, USA TODAY

BEIJING â?? A truck packed with fireworks for next week's Chinese New Year celebrations exploded Friday morning on an elevated highway in central China, collapsing a 260-foot section of road and plunging vehicles 100 feet to the ground below.

Nine people were killed and 13 others injured after at least 25 vehicles fell from the highway in Mianchi county in Henan province, reported the state news agency Xinhua.

Earlier online reports from other state media, later deleted, said the death toll was 26. Photos showed some vehicles had a narrow escape on either side of the collapsed section.

China's police ministry dispatched a team headed by a vice-minister to probe the blast, which an "initial investigation" blamed on an explosion by the truck carrying fireworks, said Xinhua.

Fireworks and firecrackers form a key part of the annual Lunar New Year celebrations in China, from traditional beliefs that they scare away evil spirits. Despite government efforts to ban low quality fireworks and improve the safety of their production, transportation and use, they continue to exact a deadly toll every year across China.

The collapse caused many Chinese to express doubts on social media about the quality of highway construction. The G30 expressway that broke apart is about 55 miles west of Luoyang, an ancient capital of China known for grottoes of Buddhist statues carved from limestone cliffs.

The expressway is China's longest road, stretching 2,700 miles from the eastern coast to the border with Central Asia. The highway network, like high-speed rail, has undergone rapid expansion in recent years, and quality problems are not uncommon.

In an unusual move even Xinhua reported the suspicions of some Internet users.

"I just cannot understand how this road was built," said 'Wushifeng 521', on the Twitter-like Sina Weibo microblogging service. "How can fireworks be so powerful? Is the viaduct a piece of shoddy construction work?" asked user 'Langren-088,' according to Xinhua.

Safety reasons caused Beijing and many other cities to ban fireworks for several years. In 2006, on the first day of the Lunar New Year, a storeroom of fireworks exploded at a temple fair in Henan, killing 36 people. In 2000, an unlicensed fireworks factory in southern China exploded, killing 33 people, including 13 schoolchildren working there.

Fireworks have been permitted again in recent years but Beijing authorities asked residents Friday to set off less fireworks this new year, which falls Feb. 10, due to concerns they will worsen the capital's already poor air quality.